Relax the NUW requirements for isKnownPredicateViaNoOverflow, if the
second operand (Y) is an ADD. The code only simplifies the condition if
C1 < C2, so if the second ADD is NUW, it doesn't matter whether the
first operand also has the NUW flag, as it cannot wrap if C1 < C2.

https://alive2.llvm.org/ce/z/b3dM7N


PR: https://github.com/llvm/llvm-project/pull/149795

Current the comparator is inconsistent when we have two external globals
and one internal globals due to
```
    if (IsGVNameSemantic(LGV) && IsGVNameSemantic(RGV))
      return LGV->getName().compare(RGV->getName());
```

The internal global compares equal to (not strictly less than) the
external globals, but the external globals are not equal.

Fixes #147862.

Update SimplifyICmpOperands to only try subtracting 1 from RHS first, if
RHS is an op we can fold the subtract directly into. Otherwise try
adding to LHS first, as we can preserve NUW flags.

This improves results in a few cases, including the modified test case
from berkeley-abc and new code to be added in
https://github.com/llvm/llvm-project/pull/128061.

Note that there are more cases where the results can be improved by
better ordering here which I'll try to investigate as follow-up.

PR: https://github.com/llvm/llvm-project/pull/144404

Having a finite Depth (or recursion limit) for computeKnownBits is very
limiting, but is currently a load-bearing necessity, as all KnownBits
are recomputed on each call and there is no caching. As a prerequisite
for an effort to remove the recursion limit altogether, either using a
clever caching technique, or writing a easily-invalidable KnownBits
analysis, make the Depth argument in APIs in ValueTracking uniformly the
last argument with a default value. This would aid in removing the
argument when the time comes, as many callers that currently pass 0
explicitly are now updated to omit the argument altogether.

Also demonstrate its use in ScalarEvolution.

Add dedicated m_scev_AffineAddRec matcher with 
complementing m_Loop() and m_SpecificLoop matchers.

PR: https://github.com/llvm/llvm-project/pull/141141

These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.